Golf club head

ABSTRACT

When a golf club head is placed in a reference state, a distance A from a lowest part of a sole to a leading edge in a vertical direction is 6 mm≦A≦10 mm. A distance B from a bottom of the face to a top of a club head main body is 14 mm≦B≦18 mm. The distances A and B satisfy a relationship 13 mm≦(A+B)/2≦19 mm. When the sole is lifted for 6 mm from the ball bottom, a center of the face is about 3.6 mm above a ball equator and 2.4 mm below the ball equator. When the distance A is the minimum value of 6 mm and the distance B is the minimum value of 14 mm, the center of the face is located at about 7.0 mm below the ball equator.

BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT

The present invention relates to a putter-type golf club head.

In playing golf, a putter is expected to reduce duff shots when used. Patent Reference 1 has disclosed a conventional golf club. A club face of the conventional golf club has a height of 22 mm.

Furthermore, Patent reference 2 has disclosed another conventional golf club. In the conventional golf club disclosed in Patent Reference 2, an intersection of a face and a sole of a putter are formed as an R-shape, and the height of the part having the R-shape is about 8 mm.

Moreover, Patent reference 3 has disclosed a still further conventional golf club. According to the paragraph [0010] of Patent Application 3, a diameter of a golf ball is set as 1.68 inches (42.67 mm) or larger as standard. Since most golf balls commercially available now have diameters of about 43 mm, so that, as for the face dimension, the diameter F of the face is to be in a range of 3.5 to 5.2 mm when B=43 mm is applied in the above formula. Needless to say, the dimension of the face would vary when the standard diameter of a ball is different. In addition, a front part . . . and has a sole (5), in which a lower edge of the face is cut in the range of 0.8 to 1.2 cm. Further, the diameter F of the face is within the range of 3.5 to 5.2 mm seems to be a typing error, and it is supposed that the diameter F of the face is within the range of 34.4 to 51.6 cm.

Patent Reference 1: Japanese Patent Application Publication No. 2003-275348

Patent Reference 2: Japanese Utility Model Application No. S56-132730 (Japanese Utility Model Application Publication No. S58-40172)

Patent Reference 3: Japanese Utility Model No. 3,147,604

According to Patent Reference 2, a lower half part of a hitting area E is to be secured for 12.05 mm or 13.15 mm at the maximum. Accordingly, in the case of the putter disclosed in Patent Reference 2, 24.10 mm or 26.30 mm is secured as a distance from the bottom of the face to the top of the club head main body in a vertical direction.

Patent Reference 1 has disclosed that the height of the face is 22 mm. However, it may be difficult that the height of the face can be 22 mm while keeping the “8 mm” dimension in the putter disclosed in Patent Reference 2. According to Patent Reference 2, the lower half part of the hitting area E is to be secured for 12.05 mm or 13.15 mm at the maximum and there is no possibility that the dimension will be an issue upon hitting. Accordingly, it is suggested that it is important to secure 24.10 mm or 26.30 mm as a distance from the bottom of the face to the top of the club head main body in the vertical direction. Here, “secure” means “surely achieve” and “surely keep/remain”, and such suggestion is an issue to achieve the face section height of 22 mm while keeping the “at least 8 mm” dimension in the putter disclosed in Patent Reference 2 as described above.

In addition, according to the putter disclosed in Patent Reference 2, the intersection between the face and the sole is formed in an R-shape, and the heights of the sections formed in the R-shapes are set about 8 mm. On the other hand, according to the putter disclosed in Patent reference 3, the distance from the lowest part of the sole to the leading edge, i.e., the lowest blade section of the face, in the vertical direction seems to be 0 mm. Therefore, those ideas are incompatible with each other. Thus, it is difficult to apply the concept of Patent reference 3 to the putter of Patent Reference 2 even if attempted. In addition, even if such application is possible, the distance from the bottom of the face to the top of the club head main body will be the values of 3.5 to 5.2 cm minus 0.8 to 1.2 cm in the vertical direction.

According to the putter disclosed in Patent reference 2, it appears to be achievable to reduce duff shots, in which a leading edge hits the ground, but the height of the face is 24.1 mm or 26.3 mm or larger. Therefore, upon hitting an equator of a ball at the center of the face in the height direction, the sole will hit the ground, which will possibly result in a duff shot. In other words, the putter disclosed in Patent reference 2 does not solve the both issues, i.e., the duff shots by leading edge and the duff shots by the sole, at the same time.

According to the putter disclosed in Patent Reference 3, the distance from the lowest part of the sole to the leading edge, i.e., the lowest blade part of the face, is considered as 0 mm in the vertical direction. Accordingly, the chance of the duff shot, in which the leading edge hits the ground, is considered to be higher. On the other hand, according to Patent Reference 3, it is achieved to reduce the duff shots by having a rear part thereof touch the ground upon fully swinging the putter.

The putter disclosed in Patent Reference 3 does not solve both the duff shots by the leading edge and the duff shots by the sole together. Here, in view of Patent Reference 3, if a player hits a ball lifting a sole of the club for 0.8 to 1.2 cm, it may be possible to expect that a duff shot, in which the leading edge hits the ground, may not occur even when the distance from the lowest part of the sole to the leading edge, the lowest blade part of the face, is 0 mm. However, this concept is incompatible at all with forming of the intersection of the face and the sole as the R-shape and having the height of the R-shaped section for around 8 mm, and is considered to be a serious issue for combining those concepts.

An object of the invention is to provide a putter-type golf club head capable of reducing duff shots. According to the present invention, it is possible to reduce two types of duff shots, a leading edge of the golf club hits the ground, and a sole of the golf club hits the ground.

Further objects and advantages of the invention will be apparent from the following description of the invention.

SUMMARY OF THE INVENTION

In order to attain the objects described above, according to the present invention, when a putter-type golf club head is placed in a reference state where a club head is placed on a horizontal surface while keeping a specified lie angle and loft angle, a distance A from a lowest part of a sole to a leading edge, that is, a lowest blade part of a face, in a vertical direction is in a range of 6 mm≦A≦10 mm. Further, a distance B from a bottom of the face to a top of a club head main body is 14 mm≦B≦18 mm. Further, the distances A and B satisfy a relationship 13 mm≦(A+B)/2≦19 mm.

According to the present invention, when the sole is lifted for 6 mm from the ball bottom, a center of the face in a height direction is about 3.6 mm above a ball equator and 2.4 mm below the ball equator, i.e., near the ball equator. In addition, when the distance A is the minimum value of 6 mm and the distance B is the minimum value of 14 mm, even when the sole is lifted only for 1.4 mm from the ball bottom, the center of the face in the height direction is located at about 7.0 mm below the ball equator.

According to the present invention, when the sole is lifted for 6 mm from the bottom of the ball having a radius of 21.4 mm, the center of the face in the height direction is located in the range of 3.6 mm above and 2.4 mm below the ball equator. When the sole is lifted for 6 mm from the bottom of the ball having a radius of other than 21.4 mm, the center of the face in the height direction is located in the range from 3.6 mm above the ball equator to 2.4 mm below the ball equator.

According to the present invention, when the distance A from the lowest part of the sole to the leading edge, that is, the lowest blade section of the face in the vertical direction, is in the range of 6 mm≦A≦10 mm, it is achievable to reduce duff shots, in which the leading edge hits the ground. At the same time, when the distance B from the bottom of the face to the top of the club head main body in the vertical direction is in the range of 14 mm≦B≦18 mm, a player tends to lift the sole from the ground. Therefore, a player swing form tends to lift the sole from the ground and it is achievable to reduce duff shots, in which the sole hits the ground.

More specifically, when a player holds a putter having the putter-type golf club head of the invention according to the claims of this patent application, since the distance B is in the range of 14 mm≦B≦18 mm, he/she visually feels the face height is low (thin). Therefore, he/she lifts the sole from the ball's bottom so as to position the center of the face in the height direction to near the ball's equator. In other words, a player tries to lift the sole from the ball's bottom to position the center of the face in the height direction to near the ball's equator, whereby it is achievable to reduce frequency of duff shots, in which the sole hits the ground. Here, if the sole is lifted for 6 mm from the ball's bottom, the center of the face in the height direction is located within 3.6 mm above the ball's equator and within 2.4 mm below the ball's equator, i.e., near the ball's equator.

Furthermore, in actual playing of golf, the sole may be occasionally lifted for less than 6 mm, but in case the distance A is the minimum value of 6 mm and the distance B is the minimum value of 14 mm, even when the sole is lifted only for 1.4 mm from the ball's bottom, the center of the face in the height direction is located at about 7.0 mm below the ball's equator. Since the distance B is 144 mm, there is about 7 mm of the face above the center of the face in the height direction. Therefore, the face hits below the ball's equator, and even in this case, it is possible to expect a certain degree of rolling of the ball. Needless to say, as long as the sole is lifted for about 2 mm or about 3 mm from the ball's bottom, it is possible to reduce duff shots, in which the sole hits the ground, better than the case of 1.4 mm.

According to the invention, it is achievable to reduce duff shots, in which a leading edge hits the ground. At the same time, it is achievable to reduce duff shots, in which a sole hits the ground.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1(A) and 1(B) are schematic views showing a putter-type golf club head according to an embodiment of the invention, in which FIG. 1(A) is an illustrative side view thereof and FIG. 1(B) is an illustrative top view thereof; and

FIGS. 2(A) and 2(B) are schematic views showing a geometrical relationship between the putter-type golf club head shown FIG. 1, the turf, a ball, etc., in which FIG. 2(A) shows a case where a sole of the golf club head is lifted for 6 mm from the ball bottom, and FIG. 2(B) shows a case where the sole of the golf club head is lifted for 3 mm from the ball bottom.

DETAILED DECSRIPTION OF THE PREFERRED EMBODIMENTS

Hereunder, a putter-type golf club head according to an embodiment of the present invention will be described with reference to the accompanying drawings. Here, the putter-type golf club head of the invention is not limited to the one described in the following embodiment, and can be embodied in various manners with suitable changes, alterations, and/or modifications within a scope of the invention.

As shown in FIGS. 1(A) and 1(B), a putter-type golf club head 1 of the embodiment includes a hosel 10 and a club head main body 11. The club head main body 11 includes a face 12 and a sole 13, and is made of a heavy material such as metal.

As shown in FIGS. 2(A) and 2(B), in the putter-type golf club head 1, in a reference state where the golf club head 1 is placed on a horizontal surface keeping a specified lie angle and a loft angle, a distance A in a vertical direction from the lowest section of the sole 13 to a leading edge of the face 12, which is a lowest blade section, is in the range of 6 mm≦A≦10 mm (preferably 6 mm≦A≦8 mm), and a distance B in the vertical direction from a bottom of the face 12 to a top of the club head main body 11 is in the range of 14 mm≦B≦18 mm (preferably 15 mm≦B≦17 mm). In addition, A+B/2 is in the range of 13 mm A+B/2≦19 mm. According to the embodiment, the values are set as A=7 mm and B=16 mm as an example. Here, the ratio B/A is within the range of 1.4≦B/A≦3.0. In a case of an example of a conventional putter-type golf club head, A is about 1 mm and B is about 25 mm, and the ratio B/A is 25.0. The distance B in the vertical direction from the bottom of the face 12 to the top of the club head main body 11 can be set equal to the distance in the vertical direction from the bottom of the face 12 to the top of the face 12.

As shown in FIG. 2(A), according to the putter-type golf club head 1, when the sole 13 is lifted for about 6 mm (4 mm from the turf 2) from a bottom of a ball 3, a center of the face 12 in a height direction thereof is 6 mm+7 mm (distance A)+8 mm (distance B/2)=21 mm from the bottom of the ball 3. The distance of 21 mm means, for example, a position slightly below an equator of a golf ball whose radius is 21.4 mm.

Here, in case the distance A is the minimum value of 6 mm, and the distance B is the minimum value of 14 mm, when the sole 13 is lifted for 6 mm from the ball's bottom, a center of the face 12 in the height direction is located at 2.4 mm below the ball's equator. In addition, in case the distance A is the maximum value of 10 mm and the distance B is the maximum value of 18 mm, when the sole 13 is lifted for 6 mm from the ball's bottom, the center of the face 12 in the height direction is located at 3.6 mm above the ball's equator. Therefore, in case of the putter-type golf club 1 having the distances A and B within the above-described ranges, when the sole 13 is in a state of being lifted for 6 mm from the ball's equator, the center of the face 12 in the height direction is within 3.6 mm above the ball's equator and within 2.4 mm below the ball's equator, i.e., near the ball's equator.

Furthermore, when the distance A is the minimum value of 6 mm and the distance B is the minimum value of 14 mm, as shown in FIG. 2(B), when the sole 13 is lifted for 3 mm from the ball's bottom, the center of the face 12 in the height direction is located at 5.4 mm below the ball's equator. In addition, in case the distance A is the maximum value of 10 mm and the distance B is the maximum value of 18 mm, when the sole 13 is lifted for 3 mm from the ball's bottom, the center of the face 12 in the height direction is located at 1.6 mm above the ball's equator.

Moreover, in case the distance A is the minimum value of 6 mm and the distance B is the minimum value of 14 mm, when the sole 13 is lifted for 2 mm from the ball's bottom, the center of the face 12 in the height direction is located at 6.4 mm below the ball's equator. Even in this case, the distance B is 14 mm, which in turn there is 7 mm of the face 12 above the center of the face 12 in the height direction. Therefore, even when the center of the face 12 in the height direction is located at 6.4 mm below the ball's equator, it is possible to hit the ball below the equator thereof with the face 12. In addition, in case the distance A is the maximum value of 10 mm and the distance B is the maximum value of 18 mm, when the sole 13 is lifted for 2 mm from the ball's bottom, the center of the face 12 in the height direction is located at 0.6 mm above the ball's equator.

In case the distance A is the minimum value of 6 mm and the distance B is the minimum value of 14 mm, when the sole 13 is lifted for 1.4 mm from the ball's bottom, the center of the face 12 in the height direction is located at 7.0 mm below the ball's equator. Even in this case, the distance B is 14 mm, which in turn there is 7 mm of the face 12 above the center of the face 12 in the height direction. Therefore, even when the center of the face 12 in the height direction is located at 7.0 mm below the ball's equator, it is still possible to hit the ball's equator with the face 12. Moreover, in case the distance A is the maximum value of 10 mm and the distance B is the maximum value of 18 mm, when the sole 13 is lifted for 1.4 mm from the ball's bottom, the center of the face 12 in the height direction is located at 0 mm above the ball's equator.

Here, as for the preferred distances A and B, according to similar calculation, it is possible to know the center of the face 12 in the height direction relative to the ball's equator, etc. when the sole 13 is lifted from the ball's bottom.

According to the above-described configuration, with the distance A, a distance from the lowest part of the sole 13 to the lowest blade part of the face 12, i.e., the leading edge, in the vertical direction is set in the range of 6 mm≦A≦10 mm, it is possible to reduce duff shots, which is caused by leading edge's hitting the ground. At the same time, with the distance B, a distance from the bottom of the face 12 to the top of the club head main body 11 in the vertical direction, is set in the range of 14 mm≦B≦18 mm, it is possible to have the sole 13 tend to be lifted from the ground and thereby it is possible to reduce duff shots, which is caused by hitting the ground with the sole 13. More specifically, when a player holds a putter, which has the putter-type golf club head configured as described in claims of the invention, since the distance B is in the range of 14 mm≦B≦18 mm, the player visually feels the face's height is small (thin), he/she lifts the sole 13 from the ball's bottom so as to position the center of the face 12 to near the ball's equator in the height direction. In other words, since the player will try to lift the sole 13 from the ball's bottom so as to position the center of the face 12 to near the ball's equator in the height direction, it is achievable to reduce the frequency of duff shots, which are cause by hitting the ground with the sole 13. Here, as also described above, when the sole 13 is lifted for 6 mm from the ball's bottom, the center of the face 12 in the height direction is located within 3.6 mm above from the ball's equator and 2.4 mm below the ball's equator, i.e., near the ball's equator. On the other hand, in case of actual playing of golf, the sole may be lifted for less than 6 mm sometimes, but even when the sole is lifted only for 1.4 mm from the ball's bottom in case the distance A is the minimum value of 6 mm and the distance B is the minimum value of 14 mm, the center of the face in the height direction is located at 7.0 mm generally under the ball's equator. Since the distance B is 14 mm, there is generally 7 mm of the face 12 above the center thereof in the height direction and the face 12 hits below the ball's equator. Therefore, even in this case, a certain level of rolling of the ball can be expected. In addition, as long as the sole 13 is lifted for as small as 2 mm from the ball's bottom, it is achievable to reduce duff shots, which are by hitting the ground with the sole 13. Needless to say, when the sole 13 is lifted for 3 mm from the ball's bottom, it is achievable to reduce duff shots more than when the sole 13 is lifted for 2 mm.

Moreover, according to the embodiment, in the putter-type golf club head 1, a face progression (a distance between a leading edge and a shaft's axis plane square to the playing direction) C is set in the range of 35 mm≦C≦50 mm (preferably 38 mm≦C≦47 mm). In addition, a width D from a heal to a toe of the head is set in the range 108 mm≦177.8 mm (preferably 120 mm≦D≦162 mm). Needless to say, when there is restriction about the golf club head in terms of rules of golf, those values are set in the range specified in such rules.

Furthermore, according to the putter-type golf club head 1 of the embodiment, when the sole's lowest part is positioned behind the shaft's axis, it is achievable to reduce topped shots even more, which are caused by head's being bounced by the ground. For example, before the sole's lowest part hits the ground, the face hits the ball.

Moreover, also when a player hits a ball from somewhere around the green towards the green using a putter having the putter-type golf club head 1, it is achievable to reduce duff shots. Furthermore, when a player hits a ball from the rough around the green towards the green, if the distance B from the bottom of the face 12 to the top of the club head main body 11 in the vertical direction is small, it is achievable to reduce resistance of the turf 2, which is significantly affected by the height of the face's surface, so that it is easy to control the club head speed at impact.

In addition, when the center of gravity of the golf club head is configured to be close an axis of the shaft attached to the hosel 10, it is achievable to stabilize the club head actions during swing.

Here, when a player swings a club in the rough, when the distance B from the bottom of the face 12 to the top of the club head main body 11 in the vertical direction is small, while the resistance the face 12 receives from the turf 2 is smaller, the resistance caused by the turf's tangling onto the neck of the golf club will not change so much. Therefore, it may increase a chance of missed shots such as a ball's traveling leftward. When the face progression C is in the range of 35 mm≦C≦50 mm, the face can hit the ball before receiving resistance from the turf 2 on the neck of the golf club, so that it is achievable to reduce a chance of the above-described missed shots.

While the invention has been explained with reference to the specific embodiments of the invention, the explanation is illustrative and the invention is limited only by the appended claims. 

What is claimed is:
 1. A golf club head, comprising: a head main body; a sole portion on the head main body; and a face portion having a leading edge at a lower portion thereof, wherein said sole portion is arranged so that a lowest point of the sole portion is away from the leading edge by a distance A in a vertical direction and the lowest point of the sole portion is away from an highest point of the head main body by a distance B to satisfy the following conditions when the golf club head is placed in a reference state where the head main body is placed on a horizontal surface while maintaining a specific lie angle and a specific loft angle: 6 mm≦A≦10 mm, 14 mm≦B≦18 mm, 13 mm≦(A+B)/2≦19 mm, said face portion is arranged so that a center of the face portion is situated near a ball equator between about 3.6 mm above and 2.4 mm below in a height direction of the face portion when the sole portion is lifted for 6 mm from a ball bottom, and said face portion is arranged so that the center of the face portion is situated at about 7.0 mm below the ball equator in the height direction of the face portion when the distance A is 6 mm and the distance B is 14 mm even when the sole portion is lifted only for 1.4 mm from the ball bottom. 